Explosively actuated tool



Nov. 17, 1942. R. TEMPLE 2,302,646

' EXPLOSIVELY ACTUATED TOOL Filed Jan. 27, 1941 i? A- Z9 Y 40 J4 y/ 24 l i .32 7 /J// 244 INVENTOR. ROBERT TEMPLE ATTORNEY.

Patented Nov. 17, 1942 EXPLOSIVELY ACTUATED TOOL Robert Temple, Swissvale, Pa., assignor to Robert Temple, Inc., Denver, 0010.

Application January 27, 1941, Serial No. 376,100

12 Claims.

This invention relates to a method and apparatus for forming an aperture or opening in a work piece such as metal rails, girders, plates and the like and, more particularly, to an improvement in an explosively actuated apparatus, or an apparatus powered by the detonation of an explosive charge against a movable tool or projectile, which renders such an apparatus, including the improvement, more adaptable as a portable apparatus for forming an aperture in a work piece and which is operable in a location where it is necessary to confine the products of explosion and the aperture forming operation to eliminate hazards.

It is an object of this invention to provide an improvement in the method and apparatus employing the explosive actuated principle of operation which makes the operating tool more effective in performing its function, reduces the maintenance cost, simplifies the use of the apparatus and provides a portable apparatus that is adaptable for use in a contaminated and combustible atmosphere such as occurs in mines.

It is a more specific object of this invention to provide an improved portable apparatus and method for forming an aperture in a work piece and employing the explosive actuation principle, which facilitates the supporting of the apparatus in operativeposition and which permits a greater force to be transferred to the aperture forming member to render the apparatus capable of forming an aperture in metal of greater thickness and strength.

In my application Serial No. 299,116, filed October 12, 1939, there is described and claimed 35 generally an apparatus and method similar to that to which the present application relates. While the apparatus in the cited application is successful and is being used for performing the operations intended, it is an object of the in- 40 stant invention to provide certain improvements thereof which render it more adaptable for the purpose intended and also lessen the cost of operation and maintanence and provide an apparatus that is especially adaptable for use in at mospheres containing combustibles.

Other objects of this invention include the simplicity of the apparatus,.low cost of manufacture and its adaptability to all shapes of work pieces within the limits of workability of the ap- 50 paratus, and further objects will become apparent from a description of a preferred embodiment which employs the principle involved in my invention and which will be more readily understood by reference to the drawing in which:

die member l5.

Fig. 1 is a side elevational view partly in section of one of the preferred embodiments of my invention;

Fig. 2 is a top plan view of the embodiment;

Fig. 3 is an end elevational view thereof; and

Fig. 4 is a view similar to Fig. 1 and illustrates in a representative manner the movement of elements of the apparatus to a position after the forming operation is completed.

Referring to the drawing and particularly to Fig. 1, the apparatus in order to be portable and entail the least amount of support necessary for supporting the operating elements necessitates some form of a frame or supporting structure such as a C-frame In which is employed in the preferred embodiment. This frame is formed of strong shock-resisting alloy steel and has leg portions I 2 and i4 made of metal of somewhat greater thickness than the main body of the frame in order to accommodate elements to be supported by the frame. The upper portion has a grip l l formed in the metal. The one leg I2 is recessed to accommodate an adjustable plug l3 that holds a die member l5 against a work piece S. This work piece is represented as a section of rail, but this represents merely one application of my invention and it is not to be construed as a limitation since many other applications can be made where the forming operation is desired. The die member l5 contains an opening it disposed axially of the member and has an outward converging surface that cooperates with a similar surface of theplug to adequately support and effectively properly position the die piece in position against the work piece. The plug, for the purpose of adjustment, is threaded to the frame and in order to be easily moved the outer end portion is knurled to provide easy movement and assembly of the die piece to the work piece. The opposite leg I4 is suitably recessed to receive a longitudinal bushing 20 that is tightly fitted into the recess and is forced up against the shoulder 20a at the inward or forward edge portion of the frame and forms a barrel or expansion chamber for the explosion apparatus. This barrel is to accommodate a movable plunger or piston 23 that carries an aperture or hole forming member 24 in its forward end portion. This member acts as a projectile and is the means provided for forming a hole or aperture in a. work piece. Preferably, this member has a greater area at its'forward end and is to be positioned when in place in the plunger in alignment with the opening it in the The plunger is actuated by the embodiment, a breech or cartridge carrying member 26 has a central passage and a recess in which a cartridge 21 is positioned. This breech is threaded intothe frame and has a forward converging surface that fits into a complementary surface of the piston and thus seals the breech to the piston when the piston is in its original or starting position. A further function of this construction is that the frictional engagement of the tapering and complementary surfaces of the plunger and breech serve to act as a retarding means in the movement of the plunger. The purpose of this means of action is disclosed in my pending application hereinabove identified. Briefly, the action is to earnpensate for the short length of barrel used in the apparatus illustrated as a preferred embodiment, and the consequent limited volume available for expansion of the gases formed in setting off the cartridge. The effect is to subject the plunger to a force adequate to move the plunger at a rate to drive the projectile carried 'by the plunger through the work piece. An

ejector 29 is threaded to the outward end of the breech and has a surface operative on the cartridge head to remove the cartridge from the breech after explosion. A firing head 30 encloses the cartridge and carries a firing pin 32 aligned with the detonator of the cartridge. This firing pin has a flange 33 that holds the pin in position due to its abutment against a collar 34 that is threaded to the head and by means of a spring 35 the pin is disposed away from the detonator and by the use of a hammer or similar instrument the pin is impacted against the detonator. The collar 34 is held in place by means of a set screw 34a.

Forming an important part of this invention is the employment of a plunger having an area that is enlarged in area over the pistons or pressure responsive members used heretofore and arranging so that the plunger moves into engagement with the work piece and carries a projectile or aperture forming member 24 at its forward end. Preferably, the projectile or punch is made separable because of cost of maintenance of the apparatus and as this is the element requiring repair and replacement. In the embodiment, it is merely fitted into a recess that is axial of the plunger and the fit is effective to hold the projectile or punch when making ready. With this arrangement, the plunger has an increased area open to the force of explosion and thus imparts greater force to-the projectile. It is this force which produces the hole forming operation and makes the apparatus increasingly effective with a similar force or pressure produced by the explosion of a charge. For the purpose of assisting the hole forming operation of the punch, it has a centering portion 24a.

' Another feature of this improvement is that the plunger and projectile are spaced a predetermined distance from the entering surface of the work piece by means of spacers or supports 40 that are threaded into the surface of the frame and accommodates the movement of the piston or plunger from the barrel. The frame has an opening communicative with the barrel and of a size to allow the piston to move through and as these spacing elements must be positioned sufficiently apart for the piston an extended flange Illa is provided and is illustrated in Figs. 2 and 3.- By positioning the plunger or piston a predetermined distance from the entering surface of the work piece and also arranging so that the inward or forward end of the barrel is open to allow the piston to move therefrom or at least a portion thereof, advantage is taken of the effect of inertia in moving the plunger and imparting greater force to the projectile to force it through the work piece. These spacing elements illustrate one manner of disposing the piston in its original or starting position in spaced relation to the work piece. The frame itself may extend against the work piece and by means of the adjustment plug held in ,a supporting relation onto the work piece. The essential factor is that there is a spaced relation between the original position of the piston, Fig. 1, and the work piece. It is preferred that the punch or projectile extend beyond the forward edge of the plunger a distance equal to about the thickness of the metal of the work piece so that as the plunger comes against the entering surface of the work piece, the forward surface of the punch or projectile is breaking through the outer or opposite surfaceof the work piece. Then as the forward surface abuts the work piece, the effect is to discharge the punchfrom the plunger and force it along with the material removed from the work piece into the recess of the die. The effect of an explosion is illustrated in Fig. 4 illustrating the abutting action of the plunger and the hole forming operation of the punch or projectile. Preferably, the plunger should have sufficient length so that when in the position as illustrated in Fig. 4, it has a portion remaining in engagement with the barrel.

A further advantage of the engagement of the plunger with the work piece is that shook ordinarily imparted to the frame is substantially eliminated in that it is taken up principally by the work piece. Furthermore, this function causes the punch or projectile to be drawn clear or separated from the plunger and discharged into the die. This operation eliminates any difficulty encountered in removing the punch from the work piece and greatly facilitates its reassembly for another operation. In orderto restore the plunger to its original position, a tool may be employed such as described in my pending application, heretofore identified (see elements 92, 94, 96, 98 in Fig. 2), and which consists of a spindle or rod that is passed through the central opening of the breech after the head and cartridge are removed and is threaded into the recess 23a of the plunger. By a hammer action the plunger is brought up against the forward surface of the breech in sealing relation. The breech block or firing head is then assembled to the breech after a cartridge is inserted and this portion of the apparatus is made ready for operation.

An important advantage of this improvement when a separable punch is mounted to the piston is that the replacement of a punch or aperture forming member 24 entails little expense. It is apparent that the punch forms a small but yet the working part of the whole apparatus and can be made at a low cost. Because the die is actually sealed to the work piece and the plunger is made long enough to continue in the barrel when abutting the Work piece, all of the explosive gases and igniting particles are contained in the apparatus during the forming operation. This makes the apparatus especially useful in atmospheres containing combustibles and makes the apparatus especially useful in mines.

Fig. 4 is a comparative illustration and represents the probable position of the working elements, that is, the plunger and punch, after the hole forming operation has been completed. The portion of material removed from the work piece is designated as S1 and the punch is shown in place in the die while the plunger or piston has been forced against the work piece. The cartridge used for this purpose is a blank cartridge containing an explosive suitable for this purpose and well within the knowledge of those skilled in the art. It is apparent that the steps of operation and the portability of the apparatus render it especially useful for the purposes intended. By the arrangement, greater effectiveness is produced by the force of explosion of a detonated charge and this permits greater use of the apparatus because of its ability to form apertures or holes in work pieces of greater thickness and strength. As previously described, this is accomplished for the most part by the increased area of the piston surface presented to the force of 1 explosion and the spacing of the engageable surface of the piston from the work piece and its abutment therewith when subjected to the force of explosion to exert an additional inertia force to the punch.

While the preferred embodiment illustrates a practical application of my invention, it is not intended that this specific support and aligning arrangement be limited thereto, since it is quite feasible that the die and explosive actuating device be separated and supported by some independent means suitable for this purpose. The only requirement is that the support be ample and that the two parts of the whole apparatus be assembled in true alignment so that the punch is effective by cooperation with the dieto form a true opening. It is preferred that the entering opening of the die be slightly larger than the size of the punch, the comparative size being a matter of available information, in order that the material is sheared properly to form a uni form area of opening. The die edge cooperates with the punch as it enters and passes through the work piece material to sever the material in a manner to form a uniform opening. That portion of the recess of the die beyond the entering portion is enlarged to permit some expansion of the material removed S1 and the punch and to prevent adherence to the surface of the die and so that both are readily removed from the die. Furthermore, as previously stated, while it is preferred that the plunger and punch or projectile be separable, it is feasible to make the plunger and projectile integral and provide the increased area of plunger to abut the work piece as the punch passes from the opposite surface and discharges the severed work piece material into the recess of the die. The disadvantage to this arrangement is the expense of replacement of the punch.

It is intended that this detailed description and operation of the preferred embodiment be construed only as one application of the principle involved in my invention and that the invention be limited only by the scope of the appended claims.

I claim: 1. In an explosively actuated .tool comprising a housing having an open end, a movable means slidably mounted in the housing and passable through the open end of the housing into engagement with a support, means connected to the housing to removably receive and detonate an' explosive charge behind the movable means, a projectile tool means associated with the movable means and operative to form an opening in the work piece and to be discharged from the movable means, a die means to be supported against the opposite surface of the work piece and in alignment with an opening to be formed in the work piece, a means to support the die means, and a means to support the housing against the work piece in alignment with the opening to be formed and to position the movable means in its starting position in spaced relation to the work 7 piece.

2. An explosively actuated tool comprising a frame member, a movable means slidably mounted in the frame and arranged to be moved from the frame intoengagement with a work piece, a

retarding means for the movable means, the frame having means to abut a work piece and to space the movable means in its starting position from the work piece, means to removably receive and detonate an explosive charge behind the movable means, a projectile tool means separably associated with the movable means and extending from the movable means and operative to form an opening in the work piece and to be discharged from the movable means, means to discharge the tool means from the movable means, and a die means carried by the frame and spaced from the spacing means to accommodate and abut the work piece interposed between and aligned and cooperative with the tool means to form an opening in-the work piece.

3. In an explosively actuated tool comprising a frame member, an explosion chamber supported by the frame and having an open end, means associated with the chamber to removably receive and detonate an explosive charge, movable means within the chamber and adapted to be subjected to the explosive charge and to be moved from the chamber, a projectile tool means separably associated with the forward end of the movable means and extending an amount equal to at least the thickness of work piece to be removed, the forward end of the movable means being positioned in spaced relation to the work piece when disposed in its starting position and movable into engagement with the work piece as the tool means passes through the material of the work piece, the association of the tool means and movable means being such that the tool means is discharged from the movable means by the impact of the movable means with the work piece, and an aligned adjustable means supported by the frame and operative to engage an opposite surface of the work tool means to form an opening in the work piece.

4. A tool operated by a confined explosive charge comprising a frame member, an explosion chamber supported by the frame member and having an open discharge end, means connected to the explosion chamber to removably receive and detonate an explosive charge, a piston member within the explosion chamber, a retarding means for the piston member, a projectile tool means supported by the'piston and'separable therefrom. an impact means for the piston member to free the projectile from the piston member. an adjustable work engaging means supported by the frame and spaced from the discharge end of the explosion chamber to accommodate a work piece positioned between the explosion chamber and the adjustable means and to attach the frame'to the work piece and the adjustable means having a chamber cooperative with the tool piece and cooperative with the means to form an aperture in the work piece and to receive and serveas an abutment for the work piece material severed and the projectile after passing through the work piece.

5. In an explosively actuated tool comprising a 5 frame member, the frame member having an explosion chamber with an open discharge end, means connected to the chamber and arranged to removably receive anddetonate an explosive charge, a piston member slidably mounted in the barrel and arranged ,to be subjected to the explosive charge and to move through the discharge end, a separable projectile tool means carried by the piston member and extending from its forward end, the piston having its forward end normally disposed in spaced relation to a work piece in its starting position and arranged to move into engagement therewith, the tool means being ar- 7 ranged to be freed from the piston member upon its impact with the work piece, an adjustable means supported by the frame and spaced from the discharge end to accommodate the work piece and operative to attach the frame to the work piece and the adjustable means having a chamber in alignment with the explosion chamber and cooperative with the tool means to form an aperture and to receive and operate as a stop means for the work piece material removed and the tool means after passing through the material of the work piece I 6. In an explosively actuated tool comprising a frame member, an explosion cylinder supported by the frame and having an inner open end, means connected with the cylinder and arranged to removably receive and detonate an explosive charge, a piston member within the cylinder adaptable to be subjected to, the explosive charge and tov move from the cylinder through the inner open end, a projectile tool means carried by the forward end of the piston and separable there- 43 from and to be discharged from the piston, a spacer means supported by the frame and arranged to engage a work piece and to position the forward end of the piston member in its starting position a predetermined distance from the 45 work piece and to permit the piston member to move into engagement with the work piece, an adjustable die means supported by the frame and disposed oppositely and in spaced relation to the engaging ends of the spacer means and in align- 5 ment with the piston member and operative to attach the frame to the work piece and the adjustable die means having a chamber and a defining surface cooperative with the tool means to sever material from the work piece to form an opening and to receive the material removed and the tool means after passing through the material.

'7. An explosively actuated tool comprising a c-frame member having an explosive chamber in one leg portion, a movable means within the chamber, a means associated with the chamber to removably receive and detonate an explosive charge, a retarding means for the movable means, the discharge end of the explosive chamber being 5 open to permit movement of the movable means therethrough, a projectile tool means carried by the discharge end of the movable means and separable therefrom, spacer means supported by the frame to dispose the normal position ofthe movable means a predetermined distance from the work piece engaged by the spacer means and to be positioned between the leg portions of the frame, the spacer means being arranged to per- H mit the movable means to pass into engagement H) with the work piece, the engagement of the tool means and the movable means being such that the tool means is discharged from the movable means upon impact of the movable means with the work piece, an adjustable means supported by the other leg of the frame and arranged to be moved inwardly to attach the frame to the work piece and the adjustable means having a die means positioned against the work piece and in alignment with the line of movement of the Projectile to cooperate with the tool means in forming an aperture in the work piece and to receive and form an abutmentfor the material removed and the tool means after passing through the work piece.

8. An explosively actuated tool comprising a c-frame member having in one leg portion an explosive chamber with its discharge end positioned towards the other leg, a piston member in the explosive chamber and arranged to be actuated by an explosive charge, means associated with the explosion chamber to removably receive and detonate an explosive charge, a punch carried by the piston member at its discharge end and separable therefrom, an adjustable means carried by the other leg and arranged to be moved toward the other leg portion to attach the frame to a work piece disposed between the leg members, a spacer means supported by the frame and operative to engage the work piece and to dispose the piston member in its normal position a predetermined distance from the work piece surface engaged thereby, the piston member being movable from its normal position in the chamber into engagement with the work piece, and the adjustable means having a die portion in its engageable end and in alignment with the punch and cooperative with the punch to form an aperture in the work piece.

9. An explosively actuated tool comprising a C-frame member having in one leg portion an explosive chamber with its discharge end open and positioned towards the other leg, 9. piston member in the explosive chamber and arranged to be actuated by an explosive charge and to move through the open discharge end into engagement with a work piece, the piston having sufficient length that when in engagement with the work piece it remains in the explosion chamber to continue the seal of the explosion chamber from the atmosphere, means associated with the explosion chamber to removably receive and detonate an explosive charge, a punch carried by the piston member at its discharge end and separable therefrom, a die means toabut an opposite surface of the work piece to cooperate with the punch to form an aperture and to receive material removed and the punch discharged, an adjustable means carried by the other leg and arranged to be moved toward the other leg portion against the die means to attach the frame to the work piece disposed between the leg members, the engagement of the die and the piston when discharged being adequate to seal each to a surface of the work piece and provide a working sealed enclosure for the punch, and a spacer means supported by the frame and operative to engage the work piece and to dispose the piston member in its normal position a predetermined distance from the work piece surface engaged thereby and to permit the piston member to move into engagement with the work piece.

10. The method of forming an aperture in a work piece of metal or the like comprising supporting a work piece in a manner to define the aperture to be made, subjecting the material within the defining means to a driving force exerted by initially confronting the material with a punching tool having a separable inertia portion of sufficient weight to provide a substantial arrestment of movement of the inertia portion of the tool to free the material within the defining means from the remaining material.

11. The method of making an aperture in a work piece of metal or the like comprising supporting a work piece on to a die, providing an explosively actuated tool having an inertia memher to be actuated by the force of explosion and carrying a separable punch having its entering end extending beyond the end of the member an amount equal to about the thickness of the Work piece to be removed, aligning the punch with the die, supporting the actuated tool to position the forward surface of the punch in spaced relation to the entering surface of the work piece, and discharging the member from the tool under the force of a detonated explosive charge into engagement with the work piece and forcing the punch through the work piece into the die to form an aperture in the work piece.

12. In an explosively actuated tool comprising a housing having a discharge end, a movable means slidably mounted in the housing, means to arrest movement of the movable means after a predetermined movement from its starting position, means connected to the housing to removably receive and detonate an explosive charge behind the movable means, a projectile tool means carried by the movable means and operative through the discharge end of the housing, the projectile tool means being associated with the movable means and to be discharged from the movable means by arrestment of movement of the movable means to transfer energy of the movable means to the projectile tool means, and a means to support the housing in alignment 'with the operation to be performed on the work piece.

ROBERT TEMPLE. 

